FIELD OF INVENTION
The Universal Power Inlet System, or UPIS, is an electrical wiring scheme using detachable or fixed power cords which allows a Power Distribution Unit, or PDU, to be easily powered by several types of electrical installations existing around the world as far as their specific electrical configurations and ratings as well as their particular physical specifications.
INTRODUCTION
Power distribution units, or PDUs, provide a way to distribute power from a single input source to a plurality of power outlets. Additional to the basic concept of power distribution, some PDUs also have the capability of controlling and monitoring key power parameters of each of these individual outlets. These PDUs are also known as intelligent power distribution units or IPDU. A typical use of IPDU is powering up a plurality of computer servers or any other IT appliances installed on data-center racks through a single power connection to the building's wiring system. For the sake of simplicity, the term PDU will be used throughout this document to refer to either the simplest form of PDU, a non-intelligent power strip, all the way to the most sophisticated metered and switched intelligent PDU with network connectivity.
In order to perform its function, the PDU needs to be connected to the building's electrical power installation which may vary in type as far a voltage and current ratings as well as its configuration on the number phase or poles. Another important factor is that each geographic location in the world may have its own standards for the electrical power systems with specific types of receptacles, phase system, voltage and current. Traditionally, a PDU would have to have different input systems to be able to connect to each of these particular electrical systems around the world. Even within a specific electrical installation, in a certain building, you may have a variety of types of power receptacles that the PDU's power input will need to match in order for it to be properly installed.
Historically the output of a PDU could be made universal by using internationally recognized, single phase receptacles, such as IEC320-C13 or IEC320-C19. These international receptacles are connected to the specific appliances' power inlets by means of adapter cords which makes the output section of a modern PDU truly universal and portable around the world. That being said, the last frontier of a truly universal and portable PDU would be solving its input circuitry limitations and specificity.
The Universal Power Inlet System, or UPIS, solves all these previously mentioned problems by providing a generic way to connect and identify many types of electrical system and properly attaching them into the PDU's power input circuitry. This is done by these 3 simple steps:
- 1. Branching out the electrical input phase(s) into 3 generic single phase banks each of them feeding n outlets;
- 2. Defining a specific wiring mapping for each of these 3 possible input configurations: 3-phase delta, 3-phase star (or wye) and single phase. Each of these input configurations are fed into the 3 generic single phase banks (this is done through specific splices for each specific input configuration);
- 3. Implementing an identification circuitry that will indicate to the system which specific input configuration is being used as well as the total power budget and any other vital information for the protection and safety compliance of the PDU.
There are two main categories that can be derived from the Universal Power Inlet System, or UPIS: the detachable power cord system and the fixed power cord system. These two systems share all the same electrical wiring map scheme as describe in this invention but differentiate from each other on the physical aspect and functionality of the power cord itself, one being detachable and the other permanently attached.
BRIEF DESCRIPTION OF DRAWINGS
Below are summarized descriptions of the drawings which are attached on the end of this document. Please refer to next section for detailed descriptions for these preferred but non-limiting diagrams and examples:
FIG. 1 shows a top level view of a Universal Power Inlet System, or UPIS, for each of the 3 possible input configuration types which depict the Universal Input Mapping & Input Type Discrimination functional block.
FIG. 2 shows the input phase to bank mapping for each type of connection with respective input type identification code.
FIG. 3 shows the ID codes summary for each input type in both binary and decimal modes.
FIG. 4 shows an exemplary way to implement the electronic circuitry capable of discriminating the ID codes of FIGS. 2 & 3 and yet keeping isolation between Primary LV and Secondary ELV/SELV circuitry on the PDU.
FIG. 5 shows the 3 detachable power cord plug types which are to be matted to universal inlet receptacle located on the PDU. On this plug/receptacle set a protective GND and 2 additional discrimination pins were added for supplementary power cord identification like, for instance, current capacity of the detachable power cord.
FIG. 6 shows an example for the current capacity code assignments for the 2 supplementary discriminations pins as described on FIG. 5 which are based on two main standardized electrical systems: North America and International (or sometimes called European)
FIG. 7 shows an exemplary way to implement the electronic circuitry capable of discriminating the ID codes of FIG. 6 and yet keeping isolation between Primary LV and Secondary ELV/SELV circuitry on the PDU.
FIG. 8 shows the detailed wire splicing scheme for each of the input configuration types into the 3 distinct single phase banks as previously shown and described in FIG. 1, FIG. 2 and FIG. 5.
FIG. 9 shows a top level view of a detachable power cord system where the PDU with its universal power input receptacle can be connected to different types of power cord.
FIG. 10 shows a top level view of a fixed power cord system where the PDU input circuitry can be connected to different types of fixed power cord which are spliced up inside the enclosure to the universal 3 independent single phase circuits topology prior to feeding the internal outlet banks.
DETAILED DESCRIPTION OF AN EXAMPLE EMBODIMENT
FIG. 1 shows the basic concept of abstraction of the power input types from the PDU's input circuitry. This abstraction is achieved by the Universal Input Mapping and Input Type Discrimination functional block 100 which maps any of the input types into 3 (or a number multiple of 3) banks of outlets 101, 102 and 103 and detects by means of special circuitry 107 which input type is currently being used. Each bank is electrically sourced by a single phase branch circuit derived from any of the following input types: 3-phase delta 104, 3-phase star (or wye) 105 and single phase 106. Each of these input types 104, 105 and 106 have unique splicing patterns that always terminate into 3 (or a number multiple of 3) individual single phase banks 101, 102 and 103. The splicing pattern is such that it allows unique identification of each input system by means of special circuitry 107 which is described in details on later section.
FIG. 2 shows the splicing scheme for each of the 3 input types. For each input type there are rows on the left which identify the phase letters while the columns on top designates, with letters as well, each of the 3 pairs of wires feeding the 3 banks. The shaded cells with dot mark links an input circuit to an output circuit while blank cells mean no connection. Just below this connection mapping there is a description of the universal input type discrimination logic which attributes binary values (1 or 0) to each of the two logic tests: if there is voltage across terminals C-F and if there is voltage across terminals C-E. The logic will attribute value 1 for absence of voltage (same potential points) and value 0 for presence of voltage (different potential point). The result is a two bit code which uniquely identifies each of the input types.
FIG. 3 shows the codes attributed to each input type as described on FIG. 2. This table shows both the binary value as well and the equivalent decimal value. This table assumes the wire splicing map and discrimination logic as shown previously on FIG. 2.
FIG. 4 shows an exemplary electronic circuit for the input type discrimination logic which operates according to descriptions provided on FIG. 2 and FIG. 3. The diodes 108a and 108b prevent negative polarity cycles from flowing into biasing circuitry while allowing positive polarity cycles to flow. The resistor 109 limits the amount of current flowing thru the circuit while the zener diode 110 creates a 100V digital step behavior. The diode 111 avoids that increased reverse voltage damages opto-coupler's 112 input led due to leakage on rectifying diodes 108a and 108b. On the secondary side of the opto-coupler 112, resistor 113 and capacitor 114 filters out all AC component and delivers a DC level of VCC (logic state 1) or 0V (logic state 0) depending whether there is or not sufficient AC voltage on the primary section of the circuit (across input terminals of diodes 108a and 108b). The opto-coupler 112, or any other means of isolation, is necessary in order to keep electrical isolation barrier between Primary LV circuits and Secondary ELV/SELV circuits inside the PDU.
FIG. 5 shows the universal connector pin assignments according to FIG. 2 for a detachable power cord system. The universal power inlet receptacle 115 is located on the PDU while plugs 116, 117 and 118 are implemented on each detachable power cord according to its input type. Detachable plug 116 is used for 3-phase delta while detachable plug 117 is used for 3-phase star (or wye) and finally detachable plug 118 is used for single phase. In each plug the unique splicing map as described in FIG. 2 is done right before the plug terminals, usually inside the plug's back shell. A protective earth or chassis pin can be added for improved safety of the connection. Two additional pins were also added to illustrate supplementary identification parameters such as current capacity of the power cord which is described on next paragraph.
FIG. 6 shows the assigned codes for the two supplementary discrimination pins deployed in this example as current capacity identification. On this table the current capacity for each code is dependent on the regional settings of the unit whether North American or International electrical standards are to be used (the term International is sometimes replaced by European on certain applications). Each pin has a numbered designation DP1 and DP2 which can be either connected to terminal E or terminal F of the universal splicing map. The circuit that performs the code discrimination is very similar to the one described previously on FIG. 4, with the return path of each circuit connected to terminal F and the main path to DP1 or DP1 which is further described on FIG. 7.
FIG. 7 shows and exemplary electronic circuit for the supplementary discrimination pins DP1 and DP2 which operates according to descriptions provided on FIG. 6. The diodes 108a and 108b prevent negative polarity cycles from flowing into biasing circuitry while allowing positive polarity cycles to flow. The resistor 109 limits the amount of current flowing thru the circuit while the zener diode 110 creates a 100V digital step behavior. The diode 111 avoids that increased reverse voltage damages opto-coupler's 112 input led due to leakage on rectifying diodes 108a and 108b. On the secondary side of the opto-coupler 112, resistor 113 and capacitor 114 filters out all AC component and delivers a DC level of VCC (logic state 1) or 0V (logic state 0) depending whether there is or not sufficient AC voltage on the primary section of the circuit (across input terminals of diodes 108a and 108b). The opto-coupler 112, or any other means of isolation, is necessary in order to keep electrical isolation barrier between Primary LV circuits and Secondary ELV/SELV circuits inside the PDU.
FIG. 8 shows the detailed wire splicing scheme for each of the input configuration types into the 3 distinct single phase banks as previously shown and described in FIG. 1, FIG. 2 and FIG. 5. There are basically 3 types of splices that will map the respective input type into the universal pinout of 3 single phase banks with pin denominations A/B, C/D and E/F. Delta load connectivity is achieved by splicing scheme 119 which feeds each bank A/B, C/D and E/F with respective pair of phases X/Z, Y/Z and X/Y. Star or Wye load connectivity is achieved by splicing scheme 120 which feeds each bank A/B, C/D and E/F with respective pairs X/N, Y/N and Z/N (where N indicates the neutral pole). Single phase load connectivity is achieved by splicing scheme 121 which feeds each bank A/B, C/D and E/F with 3 identical branches of the input circuitry X/Y or X/N depending whereas the system is dual pole without neutral or single pole with neutral. By following this unique wire splicing scheme, it is possible, using detection circuitry of FIG. 4 to achieve the ID codes as described on FIG. 2. These ID codes allow the PDU to identify which power system it is being attached to and therefore derivation of important information necessary to monitor and control each specific type of input power connection being used. Of course, on the 3-phase star (wye) connection, the fourth 3-phase star power signal (the Neutral in FIG. 8) is a singular signal and is not interchangeable with any of the other phases (X, Y, or Z in FIG. 8). On the other hand, on 3-phase delta or single phase, the phase signals are interchangeable among themselves without affecting the functionality of the inventions described.
FIG. 9 shows a top level view of a detachable power cord system where the PDU 122 with its universal power input receptacle 115 can be connected to different types of detachable power cords 123, 124 and 125. The PDU 122 contains one universal inlet receptacle 115 depicting pinout as shown previously on FIG. 5 [115] where each of the pairs A/B, C/D and E/F are connected to the 3 independent single phase banks inside the PDU 122. A 3-phase Delta load detachable power cord 123 has the Delta splice as shown on FIG. 8 [119] inside the detachable plug 116 with pinout detail as shown on FIG. 5 [116]. The other end 123a of detachable power cord 123 is to be attached to any standard power plug property mating with the 3-Phase power receptacle located on the building's electrical installation. A 3-phase Star or Wye load detachable power cord 124 has the Star or Wye splice as shown on FIG. 8 [120] inside the detachable plug 117 with pinout detail as shown on FIG. 5 [117]. The other end 124a of detachable power cord 124 is to be attached to any standard power plug properly mating with the 3-Phase+Neutral power receptacle located on the building's electrical installation. A single-phase load detachable power cord 125 has the 3 loads (or circuit branches) splice as shown on FIG. 8 [121] inside the detachable plug 118 with pinout detail as shown on FIG. 5 [118]. The other end 125a of detachable power cord 125 is to be attached to any standard power plug properly mating with the Single-Phase power receptacle located on the building's electrical installation.
FIG. 10 shows a top level view of a fixed power cord system where the PDU input circuitry can be connected to different types of fixed power cord which are spliced up inside the enclosure to the universal 3 independent single phase circuits topology prior to feeding the internal outlet banks. The PDU 126 has a 3-Phase Delta load type fixed power cord. The Delta splice 126a, as shown on FIG. 8 [119], is done inside the PDU enclosure and delivers 3 independent single-phase circuits as shown on FIG. 1 at terminals A/B 101, C/D 102 and E/F 103. The other end 126b of fixed power cord is to be attached to any standard power plug properly mating with the 3-Phase power receptacle located on the building's electrical installation. The PDU 127 has a 3-Phase Star or Wye load type fixed power cord. The Star or Wye splice 127a, as shown on FIG. 8 [120], is done inside the PDU enclosure and delivers 3 independent single-phase circuits as shown on FIG. 1 at terminals A/B 101, C/D 102 and E/F 103. The other end 127b of fixed power cord is to be attached to any standard power plug properly mating with the 3-Phase+Neutral power receptacle located on the building's electrical installation. The PDU 128 has a Single-Phase load type fixed power cord. The Single-Phase into 3 branches splice 128a, as shown on FIG. 8 [121], is done inside the PDU enclosure and delivers 3 independent single-phase circuits as shown on FIG. 1 at terminals A/B 101, C/D 102 and E/F 103. The other end 128b of fixed power cord is to be attached to any standard power plug properly mating with the Single-Phase power receptacle located on the building's electrical installation.
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.